Heretofore, metering rod lifter cams for internal combustion engine carburetors have been provided on a primary throttle shaft to raise a push rod and associated metering rods for increasing the flow of fuel upon opening of the throttle valve. It has been common to secure the cam onto the throttle shaft with a threaded connection which necessitates a screw tapping operation and the alignment of the cam with the threaded opening on the throttle shaft in order to position accurately the cam. In the event the threaded opening on the throttle shaft or the opening on the cam receiving the screw is not positioned accurately this could affect operation of the cam and provide a variable in flow test uniformity between carburetors. The cam normally has been formed heretofore as a relatively thin metal stamping which is difficult for maintaining uniformity and is subject to undue wear in certain instances.